Just got back from my communte. Been raining here and is fairly cold for the area. Anyway, I park the car with the engine still on and I rev it up to 5k...haven't heard her talk in a while , and after I see some wispy white smoke coming out of the passenger grill ?! Like exhaust smoke but thinner. Is this something to worry about? I am guessing it is the h20 from the rain evaporating from the extra heat of the rev.

What are the cons of revving up? Not enough air flow? See the guys in the exhaust sound clips doing it.

I dont think airflow has anything to do with it but I may be wrong. All I know is that revving while not moving is bad, everybody says that. I would never do that. A tech guy will have to explain it better.